US6984284B2 - Piezoelectric composites and methods for manufacturing same - Google Patents
Piezoelectric composites and methods for manufacturing same Download PDFInfo
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- US6984284B2 US6984284B2 US10/726,805 US72680503A US6984284B2 US 6984284 B2 US6984284 B2 US 6984284B2 US 72680503 A US72680503 A US 72680503A US 6984284 B2 US6984284 B2 US 6984284B2
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- 239000004593 Epoxy Substances 0.000 description 3
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- 238000002059 diagnostic imaging Methods 0.000 description 2
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- 238000002604 ultrasonography Methods 0.000 description 2
- JLQUFIHWVLZVTJ-UHFFFAOYSA-N carbosulfan Chemical compound CCCCN(CCCC)SN(C)C(=O)OC1=CC=CC2=C1OC(C)(C)C2 JLQUFIHWVLZVTJ-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
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- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
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Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/01—Manufacture or treatment
- H10N30/09—Forming piezoelectric or electrostrictive materials
- H10N30/092—Forming composite materials
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
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- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
- Y10T156/1062—Prior to assembly
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
- Y10T156/1062—Prior to assembly
- Y10T156/1064—Partial cutting [e.g., grooving or incising]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
- Y10T156/1062—Prior to assembly
- Y10T156/1074—Separate cutting of separate sheets or webs
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
- Y10T156/1082—Partial cutting bonded sandwich [e.g., grooving or incising]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/42—Piezoelectric device making
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/43—Electric condenser making
Definitions
- This invention relates to piezoelectric composites, and more particularly to piezoelectric composites for high-frequency ultrasound applications and methods of manufacturing such composites.
- ultrasonic transducers or transducer arrays that posse the properties of good sensitivity and wide frequency bandwidth.
- Conventional transducers utilizing monolithic piezoelectric material such as, for example, lead zirconate titanate (“PZT”), typically exhibit a large acoustic impedance mismatch between the transducer and the medium under test, such as, for example, water, human tissue, and the like.
- PZT lead zirconate titanate
- piezoelectric composites that are made of individual small piezoelectric elements surrounded and isolated by a polymer matrix, such as, for example, epoxy, have been proposed. These proposed small piezoelectric elements play an increasingly important role in the development of ultrasonic transducers for medical imaging.
- the most commonly used structures of piezoelectric composite consist of small strips or posts of PZT that are embedded in a host matrix of polymer material. The height of the strips or posts is normally about one half wavelength at the operating frequency.
- the conventional process for the fabrication of a piezoelectric composite begins with a monolithic slab of piezoelectric material. Slots, or kerfs, are cut into the slab using a dicing saw. The slots are then filled in with host material such as epoxy.
- host material such as epoxy.
- a two-dimensional piezoelectric composite which consists of posts and host matrix is made by cutting the piezoelectric slab in two orthogonal directions.
- the volume ratio which is the ratio of ceramic volume over the whole composite and is usually equal to the ratio of ceramic width to pitch size in the cases of conventional 1-3 and 2-2 composites, affects characteristics of the piezoelectric composite such as coupling coefficient, velocity, acoustic impedance, and the like.
- changing the volume ratio allows for the customization of the particular piezoelectric composite for the desired transducer application/design.
- the slot/kerf size is determined by the thickness of the saw blade. It is difficult to make a specific volume ratio composite when the pitch size needs to be fixed. Normally, the volume ratio is changed by using blades of different thickness, but the volume ratio is still limited by the thickness of the blades that can be chosen, particularly when the slots/kerfs to be cut are of fine dimensions.
- the present invention provides a practical method for the fabrication of composites/arrays at any volume ratio and especially, the fabrication of uniform fine scale composites/arrays for high frequency applications.
- a piezoelectric composite/array is formed at any arbitrary volume ratio by a shift cutting method.
- a first piece and second piece of a piezoelectric base slab is provided. Initially, the upper surface of each piezoelectric base slab is cut to form an array of parallel male ridges that are spaced by an array of parallel slots. The width and depth of each slot is predetermined. The first and second base slabs are then interdigitated and joined together. Because the width of each ridge is less that the width of each slot, a first gap is formed that may be filled with a polymeric material when the base slabs are interdigitated. An uncut portion of one of the base slabs is removed to form a first interdigitated piezoelectric composite slab.
- each first interdigitated piezoelectric composite slab is cut using the same pitch and slot size as the cut that was made on the original piezoelectric base slab.
- the cutting position in this shift-dicing step is shifted in a width-wise dimension by a distance equal to a portion of the ridge width.
- the remaining second ridges will consist of both piezoelectric material and polymeric fill material with a certain ratio which is determined by the shift distance of the cutting operation.
- Two such first interdigitated piezoelectric composite slabs are formed and then interdigitated by positioning them face to face and inserting the second ridges of one first interdigitated piezoelectric composite slab into the second slots of the other first interdigitated piezoelectric composite slab.
- each second ridge is less that the width of each second slot, a second gap is formed that may be filled with a polymeric material when the first interdigitated piezoelectric composite slabs are interdigitated.
- the uncut portions on one or both sides of interdigitated slab may be removed by grinding or lapping.
- a uniform composite/array with any volume ratio can be made through above described process.
- the invention disclosed herein presents a practical and easy way to produce such piezoelectric composite/array with arbitrary volume ratio for both low and high frequency applications.
- FIG. 1A is a vertical section of one base piezoelectric slab diced in accordance with an embodiment of the present invention.
- FIG. 1B is a vertical section of a pair of base piezoelectric slabs disposed in overlying registration.
- FIG. 1C is a vertical section of the pair of base piezoelectric slabs of FIG. 1B interdigitated in accordance with an embodiment of the present invention.
- FIG. 1D is a vertical section of a first interdigitated piezoelectric composite slab with a portion of the piezoelectric base slab removed.
- FIG. 2A is a vertical section of one first interdigitated piezoelectric composite slab of FIG. 1D showing portions of the slab to be removed, the portions to be removed shifted a predetermined distance in accordance with an embodiment of the present invention.
- FIG. 2B is a vertical section of one first interdigitated piezoelectric composite slab of FIG. 2A diced in accordance with an embodiment of the present invention.
- FIG. 2C is a vertical section of a pair of diced first interdigitated piezoelectric composite slabs disposed in overlying registration.
- FIG. 2D is a vertical section of the pair of diced first interdigitated piezoelectric composite slabs of FIG. 2C interdigitated in accordance with an embodiment of the present invention.
- FIG. 2E is a vertical section of a second interdigitated piezoelectric composite slab after grinding processes have been executed on the top and bottom surfaces of the second interdigitated piezoelectric composite slab.
- FIG. 3A is a vertical section of one first interdigitated piezoelectric composite slab of FIG. 1D showing portions of the slab to be removed, the portions to be removed shifted a predetermined distance in accordance with an embodiment of the present invention.
- FIG. 3B is a vertical section of one first interdigitated piezoelectric composite slab of FIG. 3A diced in accordance with an embodiment of the present invention.
- FIG. 3C is a vertical section of a pair of diced first interdigitated piezoelectric composite slabs disposed in overlying registration.
- FIG. 3D is a vertical section of the pair of diced first interdigitated piezoelectric composite slabs of FIG. 3C interdigitated in accordance with an embodiment of the present invention.
- FIG. 3E is a vertical section of an intermediate interdigitated composite slab after grinding the top surface of the intermediate interdigitated composite slab.
- FIG. 3F is a vertical section of one intermediate interdigitated composite slab of FIG. 3E showing portions of the slab to be removed, where the portions to be removed are shifted a predetermined distance in accordance with an embodiment of the present invention.
- FIG. 3G is a vertical section of one intermediate interdigitated composite slab of FIG. 3F diced in accordance with an embodiment of the present invention.
- FIG. 3H is a vertical section of a pair of diced intermediate interdigitated piezoelectric composite slabs disposed in overlying registration.
- FIG. 3I is a vertical section of the pair of diced intermediate interdigitated composite slabs of FIG. 3H interdigitated in accordance with an embodiment of the present invention.
- FIG. 3J is a vertical section of a third interdigitated piezoelectric composite slab after grinding the top and bottom surfaces of the third interdigitated piezoelectric composite slab.
- FIG. 4A is a vertical section of one first interdigitated piezoelectric composite slab of FIG. 1D showing portions of the slab to be removed, where the portions to be removed are shifted a predetermined distance in accordance with an embodiment of the present invention.
- FIG. 4B is a vertical section of one first interdigitated piezoelectric composite slab of FIG. 4A diced in accordance with an embodiment of the present invention.
- FIG. 4C is a vertical section of a pair of diced first interdigitated piezoelectric composite slabs disposed in overlying registration.
- FIG. 4D is a vertical section of the pair of diced first interdigitated piezoelectric composite slabs of FIG. 4C interdigitated in accordance with an embodiment of the present invention.
- FIG. 4E is a vertical section of an intermediate interdigitated composite slab after grinding the top surface of the intermediate interdigitated composite slab.
- FIG. 4F is a vertical section of one intermediate interdigitated composite slab of FIG. 4E showing portions of the slab to be removed, where the portions to be removed are shifted a predetermined distance in accordance with an embodiment of the present invention.
- FIG. 4G is a vertical section of one intermediate interdigitated composite slab of FIG. 4F diced in accordance with an embodiment of the present invention.
- FIG. 4H is a vertical section of a pair of diced intermediate interdigitated composite slabs disposed in overlying registration.
- FIG. 4I is a vertical section of the pair of diced intermediate interdigitated piezoelectric composite slabs of FIG. 4H interdigitated in accordance with an embodiment of the present invention.
- FIG. 4J is a vertical section of a third interdigitated piezoelectric composite slab after grinding the top and bottom surfaces of the third interdigitated piezoelectric composite slab.
- the present method for manufacturing piezoelectric composites allows the operator to readily select and manufacture a piezoelectric composite that has a predetermined desired volume ratio, which is the ratio of the volume of piezoelectric material in the piezoelectric composite to the whole volume of the composite.
- the present invention uses shift cutting with a conventional cutting element of a predetermined width.
- a shift cutting and multi-interdigitating process provides a practical and easy way to produce piezoelectric composites and related acoustic devices that have kerf widths as thin as several microns and pitch sizes below 30 microns.
- the method also allows one to fabricating an extremely fine pitch by using reliable, stiff and relatively thick cutting elements. For example, it is possible to create a 20 ⁇ m pitch composite using 80 ⁇ m cuts and 1 ⁇ 4 shift interdigitation.
- the present invention allows for the production of two-dimensional composites, composite transducers, transducer arrays and the like of arbitrary and predetermined volume ratio and fine pitch.
- a method for fabricating a first interdigitated piezoelectric composite slab 20 is shown.
- the fabrication process begins with a pair of conventional piezoelectric base slabs 10 .
- the base slab made is formed from any desired material having the appropriate electrical and acoustical properties.
- the base slab may be formed from piezoelectric material, electrostrictive material, and the like.
- Each base slab is complementary to the other, and, as shown, is diced or cut to form first kerfs or first slots of a width K and a depth D.
- Each base slab 10 has a substantially planar upper surface 11 and has a longitudinal axis.
- a first cutting operation is preformed onto the upper surface of each base slab 10 so that a first plurality of longitudinally extending slots 12 of depth D and width K are defined in the planar upper surface of the base slab.
- a first plurality of longitudinally extending ridges 14 having a width W are defined in the upper surface of each base slab therebetween the respective first slots 12 of the first plurality of slots.
- Each ridge 14 is spaced from an adjacent ridge by a width K of the first slot.
- the width W of each first ridge 14 is less than the distance K between adjacent first ridges 14 .
- the pitch P of each base slab is the width of each first ridge 14 plus the width K between the adjacent first ridges.
- FIGS. 1B and 1C show the interdigitating of the diced pair of conventional base slabs 10 .
- the upper surfaces 11 of each of the diced base slabs 10 are placed in overlying interdigitation registration with each other such that the first plurality of ridges 14 of a first base slab 10 ′ is disposed within the first plurality of slots 12 of a second base slab 10 ′′.
- the width W of each first ridge 14 is less than the width K between adjoining first ridges 14
- a first gap 16 having width K 1 is formed between each of the respective first ridges of the connected first and second base slabs.
- each first ridge of the first base slab is spaced from an adjacent first ridge of the second base slab by the width K 1 of the first gap.
- the first gaps 16 may be filled with a filling material.
- the filling material may comprise, for example, a polymeric material, such as, for example, epoxy, polymer micro-spheres, crystal bond, and the like, as is customary and standard practice in the manufacture of composite transducers, or they may be left, at least in part, unfilled.
- the diced slabs may be dry assembled and then the gap filling material may be introduced.
- at least one of the diced slabs is prewet and/or their slots filed with such gap filling material.
- any excess amount of gap filling material can be forcibly displaced as the two diced slabs are brought together and the ridges of the first slab are interdigitated with the ridges of the second slab.
- at least one of the diced slabs is prewetted and the diced slabs are interdigitated and pulled together through capillary forces and/or atmospheric forces induced by a controlled withdrawal of excess gap filling material.
- the gaps may not be completely filled or that they are only filled temporarily as some or the entire gap filling material is removed using conventional methods.
- the portion of the base slab 10 that extends above notional line 17 is ground, lapped away or otherwise removed to form a first interdigitated piezoelectric composite slab 20 .
- the removal of the gap filling material, if desired, is most easily and conveniently achieved after removal of the piezoelectric material above the notional line 17 .
- the first interdigitated piezoelectric composite slab 20 has a pitch P 1 that is less than the pitch P of the respective first and second base slabs.
- the pitch P 1 is the width W 1 (here, the width W of the first ridge 14 ) plus the width K 1 of the first gap 16 .
- the volume ratio of the first interdigitated piezoelectric composite slab 20 is less than the volume ratio of the uncut piezoelectric base slabs.
- the present invention provides for multi-interdigitizing to provide for piezoelectric composites having fine kerf sizing.
- a pair of first interdigitated piezoelectric composite slabs 20 is provided.
- Each first interdigitated piezoelectric composite slab 20 has a substantially planar upper surface 21 and a longitudinal axis.
- Each first interdigitated piezoelectric composite slab is complementary to the other, and, as shown, is diced or cut in a shift-dicing step to form second kerfs or second slots of a width K and a depth D.
- a second cutting operation is performed on the upper surface of each first interdigitated piezoelectric composite slab 20 .
- the second cutting operation is spaced a distance S 1 that is a fraction of the pitch P from the original cutting, which, in this example, is 1 ⁇ 4 the pitch P.
- the cutting position in this shift-dicing step is shifted in a width-wise dimension by a distance equal to a portion of the first ridge width.
- other fractions of the pitch P are contemplated for the shift distance S 1 of the second cutting.
- a second plurality of longitudinally extending slots 22 of depth D and width K are defined in the upper surface 21 of the first interdigitated piezoelectric composite slab 20 .
- a second plurality of longitudinally extending ridges 24 having a width W and spaced by respective second slots 22 of the second plurality of slots 22 are defined in the upper surface of each first interdigitated piezoelectric composite slab 20 .
- the distance S 1 that the second cutting is shifted from the first cutting is less than the width of the second ridge.
- at least one of the second plurality of longitudinally extending ridges 24 includes the first gap 16 , which may be filled with the gap filling material.
- each second ridge 24 is spaced from an adjacent second ridge by a width K of the second slot 22 .
- the width W of each second ridge 24 is less than the width K between adjacent second ridges 12 .
- the pitch P of each diced first interdigitated piezoelectric composite slab is the width of each second ridge 24 plus the width K between the adjacent second ridges.
- FIGS. 2C and 2D show the interdigitating of the diced pair of first interdigitated piezoelectric composite slabs.
- the upper surfaces 21 of each of the diced first interdigitated piezoelectric composite slabs are placed in overlying interdigitation registration with each other such that the second plurality of ridges 24 of one diced first interdigitated piezoelectric composite slab is interdigitated with the second plurality of slots of the other diced first interdigitated piezoelectric composite slab.
- a second gap 26 having a width K 2 is formed between each of the respective second ridges of the interdigitated diced first interdigitated piezoelectric composite slabs.
- the width of each second ridge is less than the width K between adjacent second ridges.
- the width K 2 of the second gap is substantially equal to the width K 1 of the first gap.
- the second gaps may be filled with a polymeric material as described above.
- a portion of the diced first interdigitated piezoelectric composite slabs that extends above notional line 27 is ground, lapped away, or otherwise removed to form a second interdigitated piezoelectric composite slab 30 .
- a portion of the diced first interdigitated piezoelectric composite slabs that extends below notional line 29 is ground, lapped away, or otherwise removed to form an alternative embodiment of the second interdigitated piezoelectric composite slab 30 .
- the second interdigitated piezoelectric composite slab 30 has a pitch P 2 that is less than the pitch P 1 of the first interdigitated piezoelectric composite slab 20 .
- the volume ratio of the second interdigitated piezoelectric composite slab 30 is less than the volume ratio of the first interdigitated piezoelectric composite slab 20 .
- the pitch P 2 is greater than second ridge width W 2 which is greater than gap width K 2 .
- repeated shift dicing of composite slabs can produce piezoelectric composites of varying predetermined volume ratios.
- the cutting operations on the respective diced composite slabs may be shifted as desired to produce interdigitated composite slabs of desired volumetric ratio.
- the steps of shift dicing and interdigitating can be cycled repeatedly to produce finer pitch piezoelectric composite slabs.
- each first interdigitated piezoelectric composite slab is complementary to the other, and, as shown, is diced or cut in a shift-dicing step to form second kerfs or second slots of a width K and a depth D.
- Each first interdigitated piezoelectric composite slab 20 has a substantially planar upper surface 21 .
- a second cutting operation spaced a distance S 1 that is a fraction of the pitch P from the original cutting is performed on the upper surface of each first interdigitated piezoelectric composite slab 20 .
- the second cutting operation is shifted 1 ⁇ 8 of the pitch P.
- the cutting position in this shift-dicing step is shifted in a width-wise dimension by a distance equal to a portion of the first ridge width.
- a second plurality of longitudinally extending slots 22 of depth D and width K are defined in the upper surface 21 of the diced first interdigitated piezoelectric composite slab 20 .
- a second plurality of longitudinally extending ridges 24 having a width W and spaced by respective second slots 22 of the second plurality of slots 22 are defined in the upper surface of each diced first interdigitated piezoelectric composite slab 20 .
- the distance S 1 that the second cutting operation is shifted from the first cutting operation is less than the width of the second ridge.
- at least one of the second ridges 24 includes the first gap 16 , which may be filled with the gap filling material.
- each second ridge 24 is spaced from an adjacent second ridge by a width K of the second slot 22 .
- the width W of each second ridge 24 is less than the width K between adjacent second ridges 12 .
- the pitch P of each diced first interdigitated piezoelectric composite slab 20 is the width of each second ridge 24 plus the width K between the adjacent second ridges.
- FIGS. 3C and 3D show the interdigitating of the diced pair of first interdigitated piezoelectric composite slabs.
- the upper surfaces 21 of each of the diced first interdigitated piezoelectric composite slabs are placed in overlying interdigitation registration with each other such the second plurality of ridges 24 of one diced first interdigitated piezoelectric composite slab is interdigitated with the second plurality of slots of the other diced first interdigitated piezoelectric composite slab.
- a second gap 26 having a width K 2 is formed between each of the respective second ridges of the interdigitated diced first interdigitated piezoelectric composite slabs because the width of each second ridge is less than the width K between adjacent second ridges.
- width K 2 of the second gap is substantially equal to the width K 1 of the first gap.
- the second gaps may be filled with a polymeric material as described above.
- each intermediate interdigitated composite slab is complementary to the other and has a substantially planar upper surface 31 that is diced or cut in a shift-dicing step to form third kerfs or third slots of a width K and a depth D.
- a third cutting operation spaced a distance S 2 that is a fraction of the pitch P from the second cutting operation is performed on the upper surface of each intermediate interdigitated composite slab 30 .
- the third cutting operation is shifted 1 ⁇ 8 of the pitch P from the second operation.
- the cutting position in this shift-dicing step is shifted in a width-wise dimension by a distance equal to a portion of the second ridge width.
- a third plurality of longitudinally extending slots 32 of depth D and width K are defined in the upper surface 31 of the diced intermediate interdigitated composite slab 30 .
- a third plurality of longitudinally extending ridges 34 having a width W and spaced by respective third slots 32 of the third plurality of slots 32 are defined in the upper surface of each diced intermediate interdigitated composite slab 30 .
- the distance S 2 that the third cutting is shifted from the second cutting is less than the width of the third ridge.
- at least one of the longitudinally extending third ridges 34 includes the first gap 16 and the second gap 26 , which may be filled with the gap filling material.
- each third ridge 34 is spaced from an adjacent third ridge by a width K of the third slot 32 .
- the width W of each third ridge 34 is less than the width K between adjacent third ridges 34 .
- the pitch P of each diced intermediate interdigitated composite slab is the width W of each third ridge 34 plus the width K between the adjacent third ridges.
- FIGS. 3H and 3I show the interdigitating of the diced pair of intermediate interdigitated composite slabs 30 .
- the upper surfaces 31 of each of the diced intermediate interdigitated composite slabs are placed in overlying interdigitation registration with each other such that the third plurality of ridges 34 of one diced intermediate interdigitated composite slab 30 ′ is interdigitated with the third plurality of slots of the other diced intermediate interdigitated composite slab 30 ′′.
- a third gap 36 having a width K 3 is formed between each of the respective third ridges of the interdigitated diced intermediate composite slabs 30 because the width of each third ridge is less than the width K between adjacent third ridges.
- the width K 3 of the third gap and width K 2 of the second gap are substantially equal to the width K 1 of the first gap.
- the third gaps may be filled with a polymeric material as described above.
- a portion of the diced intermediate interdigitated composite slab that extends above notional line 37 is ground, lapped away, or otherwise removed, to form a third interdigitated piezoelectric composite slab 40 .
- a portion of the diced intermediate interdigitated composite slab that extends below notional line 39 is ground, lapped away, or otherwise removed, to form an alternative embodiment of the third interdigitated piezoelectric composite slab 40 .
- the third interdigitated piezoelectric composite slab 40 has a pitch P 3 that is less than the pitch P 2 of the respective second interdigitated piezoelectric composite slab.
- the volume ratio of the third interdigitated piezoelectric composite slab 40 is less than the volume ratio of the second or first interdigitated piezoelectric composite slabs.
- FIGS. 4A–4J illustrates another example of cycled multidigitation.
- the second cutting operation is shifted a distance S 1 that is approximately 1 ⁇ 6 of the pitch P and the intermediate interdigitated composite slab is formed as outlined above.
- a third cutting operation is made on the upper surface of the intermediate interdigitated composite slab 30 .
- the third cutting is shifted a distance S 2 that is approximately 1 ⁇ 6 of the pitch P.
- the diced intermediate interdigitated composite slabs are then interdigited and the portions of the uncut piezoelectric material are removed to form the third interdigitated piezoelectric composite slab 40 .
- the present invention provides a method for producing piezoelectric composite slabs having a desired volume ratio.
- the method uses shift cutting and multi-interdigitating.
Abstract
Description
Claims (16)
Priority Applications (7)
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US10/726,805 US6984284B2 (en) | 2003-05-14 | 2003-12-03 | Piezoelectric composites and methods for manufacturing same |
JP2006530716A JP4869932B2 (en) | 2003-05-14 | 2004-05-14 | Piezoelectric composite and manufacturing method thereof |
AT04733053T ATE378696T1 (en) | 2003-05-14 | 2004-05-14 | PIEZOELECTRIC COMPOSITE MATERIALS AND PRODUCTION METHODS THEREOF |
CA2524654A CA2524654C (en) | 2003-05-14 | 2004-05-14 | Piezoelectric composites and methods for manufacturing same |
EP04733053A EP1625630B1 (en) | 2003-05-14 | 2004-05-14 | Piezoelectric composites and methods for manufacturing the same |
DE602004010097T DE602004010097T2 (en) | 2003-05-14 | 2004-05-14 | PIEZOELECTRIC COMPOSITE MATERIALS AND MANUFACTURING METHOD THEREFOR |
PCT/IB2004/002132 WO2004102795A2 (en) | 2003-05-14 | 2004-05-14 | Piezoelectric composites and methods for manufacturing same |
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US47023503P | 2003-05-14 | 2003-05-14 | |
US10/726,805 US6984284B2 (en) | 2003-05-14 | 2003-12-03 | Piezoelectric composites and methods for manufacturing same |
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US6984284B2 true US6984284B2 (en) | 2006-01-10 |
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EP (1) | EP1625630B1 (en) |
JP (1) | JP4869932B2 (en) |
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CA (1) | CA2524654C (en) |
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WO2008011634A2 (en) * | 2006-07-21 | 2008-01-24 | University Of Southern California | Post positioning for interdigital bonded composite |
US20090065645A1 (en) * | 2007-02-05 | 2009-03-12 | United Technologies Corporation | Articles with reduced fluid dynamic drag |
US8310133B2 (en) | 2007-10-29 | 2012-11-13 | Visualsonics Inc. | High frequency piezocomposite with triangular cross-sectional shaped pillars |
US9211110B2 (en) | 2013-03-15 | 2015-12-15 | The Regents Of The University Of Michigan | Lung ventillation measurements using ultrasound |
US20200171542A1 (en) * | 2018-11-29 | 2020-06-04 | Lg Display Co., Ltd. | Vibration generating device and electronic apparatus including the same |
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JP4222467B2 (en) * | 2002-04-18 | 2009-02-12 | テイカ株式会社 | Composite piezoelectric material and manufacturing method thereof |
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WO2014025076A1 (en) * | 2012-08-08 | 2014-02-13 | 알피니언메디칼시스템 주식회사 | Method for aligning composite and apparatus therefor |
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Also Published As
Publication number | Publication date |
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CA2524654A1 (en) | 2004-11-25 |
CA2524654C (en) | 2014-08-12 |
JP2007501529A (en) | 2007-01-25 |
ATE378696T1 (en) | 2007-11-15 |
US20040227429A1 (en) | 2004-11-18 |
JP4869932B2 (en) | 2012-02-08 |
DE602004010097D1 (en) | 2007-12-27 |
WO2004102795A2 (en) | 2004-11-25 |
WO2004102795A3 (en) | 2005-01-13 |
EP1625630A2 (en) | 2006-02-15 |
DE602004010097T2 (en) | 2009-03-19 |
EP1625630B1 (en) | 2007-11-14 |
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